Flexible connector



June 28, 1949. R, ROBlNsON ETAL 2,474,690

FLEXIBLE CONNECTOR Filed Jan. 22, 1946- ITNESSES:

mill

@uw glumgm!! Patented `lune 28, 1949 FLEXIBLE CONNECTOR Lawrence R. Robinson, Dormont, `KylevlI Robinson, Glenshaw, and` Earl 0.;

Berger, Bellevue.

p Pa., assignors to Pittsburgh-PipeCleaner Company, Pittsburgh, Pa., a corporation of Pennsylvania Application January 22, 1946, Serial No. 642,'598

3 Claims. 1

This invention relates to flexible connectors, and: more particularly to those that connect axially spaced elements of pipe cleaning apparatus.

In one type of apparatus for cleaning deposits from` the inside of tubes and pipes, a plurality of scraping; devices are disposed in tandem relation inffront of a series off iluid pressure cups, and all of these elements are connected together by flexiblemeans which permit them to travel around bends in pipes when fluid pressure is applied to the back ofthe cups to force them through the pipes. Inthe past the diierent elements have.

been coupled together by strong coil springs flexible enough to permit the cleaning apparatus to travel around pipe bends if not toc sharp. However, in going around 90 oftenwould bend so farr that they Would buckle or kink and not return to their original straightness. longer perform properly and might become stuck in the pipe.

Itis among the objects of this invention to provide a flexible connector which is especially suitable for pipecleaning apparatus, which is strong and durable, which will not break in use,` and the bending of` which is positively limited so that it can not buckle or stretch out o1?v shape.

In accordance with this invention a normally straight flexible tubular member, preferably a coil spring, supports couplings at its opposite ends. Extending through the coil is a normally slack flexible tension member, such as a chain, connected to the couplings. The slack in the chain is lsuch as to permit the coil to be bent in an arc of about 90 before the chain is stretched taut to prevent further bending of the coil. The coupling members most suitably are sleeves slidablymounted on the ends of the coil and provided with cross members or transverse walls having central openings in which are mounted anchor members to which the ends of the chain are connected. These anchor members preferably are slidable axially to a limited extent in the sleeves and are prevented from rotating therein. A second coil spring may be disposed in the outer coil to reinforce it.

The preferred embodiment of the invention is illustrated in the accompanying drawings in which Fig. 1 is a side View, partly broken away, showing our flexible joint; Figs. 2 and 3 are cross sections taken on the lines II-II and III-III, respectively, of Fig. 1; Fig. 4 is a reduced side view showing several of these connectors in use in bends such coil springs- The cleaning apparatus` then would no 2 pipe cleaning apparatus; and Fig. 5 isa longitudinal section through the connector showingit bent about l909.

lReferring to Figs. 1 to 3fof the drawings, a pair of coupling sleeves` I and 2 are slidably mounted' on` the oppositefends of a heavystra-ight` coil spring 3. Thesleeves project from the ends ofi` the coil. and have their outer endy portions threaded so that theyfcan: be `screwed into other couplings by which4 this connector is joined to; the elements it is to connect. Beyond the end` of. the coil. each sleeve is providedinteriorly withl a transverse vv'all` 4 `having a central opening through it;` Slidablyl mounted in the opening in sleeve I isthe head-6 o-f. an anchor member which has a flange 1 on its inner end'engageable withr wall 4. the` wal-1` and has a threaded stem 8 integral with its outer end. Awasher 9` is held` against the outer end of the head by a pair lof lock nuts I0 screwed on the stem.

The. anchor member in the other sleeve includes' a nut-likeY member atits 'inner end engageable with wall 4. Threaded` through this member is axstud `Ill on Whicha` pair of lock nuts I6 are mounted for pressing.

a washer I'I against the outer 'end `of the nut.l

member. This stud of.` the nut member.

Welded to ilange l of the rst anchor member and tothe `inner end` of stud I4 are the end` links of a chain I8 by which the` two anchor members are connected. This chain therefore holds.

projects from theinner end the sleeves on the opposite ends of coil 3. TheV ends-of the coil are` bent radially inwardly and extend through Ithe end links of the chain to limit outward movement of the sleeves on the coil andi to prevent the two anchor members from turning on their common axis relative to eachother. By making the openings in walls 4 ofthe sleeves .square or some other non-circular shape, and makingtheportions of the anchor members therein the same shape, the sleeves will not be able to turn on the anchors. As each sleeve is prevented from rotating relative to the other, any elements that are connected together by this connector are held in predetermined positions relative to each other. This is especially desirable when the connector is used for connecting the Scrapers 20 and driving cups ZI of pipe cleaning apparatus such as shown in Fig. 4. In such apparatus the back set of Scrapers should be staggered relative to the front set and not allowed to rotate to the point where they will track behind the front Scrapers. This pipe clean- The head is` considerably thicker than.

I2 having a flange I3.:

ing apparatus can be forced through'a pipe by hydraulic or pneumatic pressure against the inside of the cups, or itcan be dragged through by a cable connected to the eyefbolt 22 projecting from the front set of Scrapers.

There normally is slack in chain I8 so that the coil 3 can bend axially to allow the cleaning apparatus to pass through a bend in the pipe being cleaned. As it is the purpose of this invention to provide a connector that will bend in an arc of about 90, the spring should permit that much bending of the coil, but no more. However, due to space limitations inside the coil, and to the fact that the slack chain is likely to kink if there are too many links in it, nthe chain is not provided with enough slack to permit a 90 bend of the coil if the end links remain inthe positions they occupy in Fig. 1. The shortness of the chain is compensated for by the fact that when the coil bends, the tension on the chain causes its end links to bend the radial ends of the spring therein inwardly'into the body of the coil. The chain therefore slides head 6 and nut member I2 inwardly in transverse walls 4 of the coupling sleeves until washers 9 and Il strike those walls. Further tension on the chain pulls the sleeves inwardly on the coil spring until their Walls 4 engage the ends of the spring, all as shown in Fig. 5. By this time the coil has bent about 90 between the two sleeves, but any attempt of the spring to bend further, which might cause it to buckle, is prevented by engagement of the taut chain with the coil at the inside of the bend. To reinforce the coil and to eliminate any chance of the chain being broken bythe strain placed on it, another coil spring 23 may extend through the outer coil loosely enough to avoid binding therein. The inner coil increases the resistance of the outer coil to buckling,` and thereby relieves the chain of some strainthat otherwise would befplaced on it. However, the inner coil does not interfere with resilient flexing of the connector as would be the case if only the outer coil were used and it was made Of'heavier stock. Best results are obtained by using an inner coil that is wound in the direction opposite to the winding of the outer coil.

According to the provisions of the patent statutes, we have explained the principle and construction of our invention and have illustrated and described what we now consider to represent its best embodiment. However, we desire to have it understood, that within the scope of the appended claims, the invention may bepracticed otherwise than as speciiically illustrated and described.

We claim:

l. A flexible connector comprising a normally straight coil spring, coupling sleeves mounted on the opposite ends of said coil and projecting therefrom, the projecting portions of the sleeves being provided interiorly with transverse walls having central openings therethrough, a normally slack flexible tension member extending through the coil, means anchored in one of said openings Y openings, and means for retaining said nut-like i member in said other opening.

2. A flexible connector comprising a normally straight coil spring, coupling sleeves mounted on the opposite ends of said coil and projecting therefrom, the projecting portions of the sleeves being provided interiorly with transverse walls having central openings therethrough, a normally slack flexible tension member extending through the coil, means anchored in one of said openings and connected to one end of said tension member, a threaded stud connected to the other end oi the tension member, a nut-like member on said stud and slidably disposed in the opening in the other of said walls from which it projects outwardly, means mounted on the inner end of said nut-like member for limiting movement of it outwardly in said wall, a washer mounted on the portion of said stud projecting from said nut member, and a nut screwed on said stud and pressing said washer against the outer end of said nutl member.

3. A flexible connector for axially spaced pipe cleaning devices, comprising a normally straight coil spring, coupling sleeves loosely mounted on the opposite ends of said coil and projecting therefrom, the projecting portions of the sleeves being provided interiorly with transverse Walls having non-circular central openings therethrough, non-circular anchor members mounted in said openings, and a normally slack chain ex; tending through said coil and connected to said anchor member, the ends of said coil extending through the chain links at the opposite ends of said chain, whereby the pipe cleaning devices are held against rotation relative to each other.

LAWRENCE R. ROBINSON. KYLE I. ROBINSON. EARL O. BERGER.

REFERENCES CITED The following referenices are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 317,157 Lowrie May 5, 1835 406,958 Seely Apr. 9, 1889 973,901 Witzenmann Oct. 25, 1910 1,212,685 Robinson Jan. 16, 1917 1,272,678 Kroll July 16, 1918 1,429,146 Krage Sept. 12, 1922 2,139,702 Tanner Dec. 13, 1938 

